Police were called at 6.56pm on Tuesday, 2 November to reports of a black Mercedes in collision with a pedestrian on Edge Hill Court, SW19.
Officers and the London Ambulance Service attended. The 83-year-old man was taken to a south London hospital in a critical condition.
Despite the efforts of medical staff, he died on the afternoon of Wednesday, 3 November. His next of kin has been informed.
The driver stopped at the scene and is helping officers with their investigation. There have been no arrests.
Detectives from the Roads and Transport Policing Command are investigating and would like to speak with anyone who saw the collision, or captured it on dash cam.
Anyone with information is asked to call the Serious Collision Investigation on 020 8543 5157 or via 101 quoting reference CAD 7789/02Nov.